1. Field of the Invention
The present invention relates generally to internal combustion engines equipped with generators. More particularly, the present invention relates to improved structure for cooling a vehicular generator mounted on an internal combustion engine, by splashing the generator internally with cooled engine oil from the engine's oiling system.
2. Description of the Background Art
It is known in the art to provide a cooling structure for a generator in a vehicle. In one example of a previously known cooling structure for a vehicular generator, oil is sprayed on an outer rotor of the generator by jetting oil toward an annular space formed between a peripheral surface of the outer rotor and an inner surface of a generator cover. A generator employing such a cooling structure is disclosed, for example, in JP Patent No. 2986470.
In the structure for cooling the generator disclosed in JP Patent No. 2986470, a jet nozzle (an oil jet) directs a jet of oil toward the annular space between the generator's outer rotor and the inner surface of the generator cover. The jet nozzle is fitted and fastened into an end of a dedicated oil passage bored in an engine crankcase, where the passage is provided for use in cooling the generator.
In the disclosure of JP Patent No. 2986470, the oil passage for cooling the generator communicates with an oil gallery in the crankcase. Therefore, oil discharged by the drive of an oil pump reaches the oil passage, formed for cooling the generator, through the oil gallery, and is jetted outwardly from the jet nozzle toward the generator's annular space.
In the structure for cooling the generator disclosed in JP Patent No. 2986470 as described above, a dedicated oil passage is required to be formed in the crankcase to cool the generator, where this oil passage is used only to deliver oil to the oil jet, and thus a process for forming the dedicated passage in the crankcase is required, whereby the manufacturing cost is increased.
In addition, since a path of the oil passage that reaches the required position in which the jet nozzle is arranged is required to be determined in consideration of the overall form and workability of the crankcase, it is not easy to form a compact crankcase which includes the oil passage.
The present invention is made in view of the above-described problem, and it is one object of the invention to provide cooling oil delivery structure for a vehicular generator in which oil is supplied to an oil jet in a required position, is jetted from the oil jet and can cool the generator, without requiring formation of a dedicated oil passage for supplying oil to cool the generator.